This entire recipe can be made in your blender!
1) Puree the tomatoes, serrano chile, and half of the cubed watermelon in the blender together.
2) Pulse in the red wine vinegar and olive oil.
3) Add the minced red onion, cucumber and dill and pulse together.
4) Season to taste with salt and pepper.
5) Puree until smooth.
6) Pour into chilled bowls and sprinkle with dill, feta, and remaining watermelon cubes.
7) Enjoy!